Mitsubishi Denki Kabushiki Kaisha

Sachio Uehara, Director General, Technical Research and Development

Michimasa Kondo

Takahiko Fujisaka

Tetsuo Kirimoto

Yoshimasa Oh-Hashi

Yoshimasa Ohashi

Kohei Nomoto

Kazuhiko Yamamoto

Masashi Mitsumoto

Shigeho Inatsune

Ryuzaburo Usui

Masafumi Iwamoto

Takahiko Sugimoto

Natsuki Kondo

Seiichi Maeda

Masatoshi Kawase

Shingo Tsujimichi

A parallel computer having a plurality of cluster buses 2 which are connected to the processor (PE) 1 via the selectors 6. The selectors 6 maintain the same condition until the next instruction is received. In this system, the clusters 11 are reconstructed at appropriate timing during the operation of the processor, thus allowing the number of processors PEs in a cluster to be exchanged in response to variation in the process load allocated to each cluster 11. Accordingly, the resources of the computer are used more effectively. The execution environment of each process may be independent. Real time execution of each process can be assured.

Parallel computer with reconstruction of processor clusters

A vehicle ID radar system has a simple construction and obtains high identifying performance by making a general identification based on a plurality of responses. There are provided an antenna for obtaining a plurality of question signals from a base station radar unit, a receiver for processing the signals received from the antenna, a question code demodulator for demodulating question codes from the received signals, a question code decoder for decoding the question codes and reading responses respectively corresponding to the plurality of questions from a plurality of data bases, a response code generator for generating response signals, and a transmitter for modulating the response signals and supplying them to the antenna.

Moving target identifying system in a base station radar unit for

A stabilizing method of a synthetic aperture radar and a position determining method by the radar. At least three repeaters are arranged in mutually different positions on the ground or the sea and a radio frequency signal having a predetermined frequency is transmitted from the radar mounted on a radar platform such as an aircraft to the repeaters. Each repeater frequency-modulates and amplifies the received signal to return the signal to the radar. The radar receives the signal returned from each repeater. The radar calculates a distance between the radar platform and each repeater on the basis of a time required for the transmitting and the receiving and phase information of the received signal. When the position of each repeater is known, by using the positions of the repeaters and the calculated distances, the position of the radar platform can be calculated. On the basis of the obtained position of the radar platform, a reference signal for phase compensation is generated. The radar eliminates a phase variation of a reflected wave received from an object to be acquired by multiplying the reflected wave by the reference signal for phase compensation.

Stabilizing method of synthetic aperture radar and position determining

A radar signal processor for use in a pulse radar system. Reception signals are given from a range divide and output circuit to a plurality of integration point variable coherent integrators, each of which is allocated to a different range domain. The range domain is given to an integration point setting section provided corresponding to each integration point variable coherent integrator. The integration point setting section determines the number of coherent integration points based on the given range domain and sets it in the corresponding integration point variable coherent integrator. The signal resulting from coherent integration by the integration point variable coherent integrator is discriminated to frequencies, then supplied to any square detector for square detection for each frequency component. Square detection output is fed into a CFAR detector, which then makes its false alarm rate constant for a supply to a display, etc.

Radar signal processor and pulse doppler radar system therewith

A fuzzy inference apparatus in which a new membership function is synthesized from a current, weighted membership function and a previously synthesized membership function fed back from a previous operation and in which a new inference value is derived from the newly-synthesized membership function. The apparatus also includes, in one embodiment, weighting apparatus for weighting the previously synthesized membership function according to the degree of response of a selected process characteristic of the process in relation to the previously synthesized membership function.

Recurrent fuzzy inference apparatus

A synthetic aperture radar system is mounted in a moving platform. The synthetic aperture radar system includes a multi-beam antenna having a plurality of reception beams different in direction from one another, the multi-beam antenna being adapted to receive radar echoes from objects. The width of each of the reception beams is selected such that the band width of a Doppler shift contained in the radar echo of a moving object is broader than that of a Doppler shift contained in the radar echo of a stationary object. The radar echo is pulse compressed to improve the range resolution before the frequency thereof is shifted such that the center frequency of the Doppler shift due to the velocity of the moving platform becomes zero. After the frequency shifting, the radar echo is filtered to separate the radar echoes of the moving and stationary objects from each other. The radar echoes of the moving and stationary objects are respectively subjected to Fourier transform with respect to the distance between the moving platform and the objects. The spectrum of the radar echo from the moving object is further shifted such that the center frequency of the Doppler shift due to the velocity of the object becomes zero. These reception, pulse compression, frequency shift and Fourier transform are executed for each reception beam. The spectrums in the radar echoes of the moving and stationary objects are respectively synthesized for all the reception beams. After the synthesization, the spectrums are respectively multiplied by a reference spectrum in the complex manner. The results of the multiplication are respectively inverse transformed from the spectrums.

Synthetic aperture radar system

A radar system having a phased array antenna for transmission and a digital beam forming antenna for reception for observing a plurality of targets by transmitting transmission pulses to the respective targets comprises a subtraction control circuit, a transmission timing control circuit and a transmission beam direction control circuit. The substraction control circuit calculates a required number of transmission pulses (beams) to be transmitted for each of transmission cycles in accordance with detected Doppler frequencies of the targets, so as not to cause ambiguity on the detected Doppler frequencies, and determines a beam direction for each of transmission beams. The timing control circuit and beam direction control circuit control transmission timing and direction of the beams.

Radar system

A multiple-beam antenna system capable of forming a plurality of beams at one time in different directions. The antenna system has a plurality of element antennas arranged in a predetermined configuration. A signal received by each element antenna is converted to a digital signal which in turn is subjected to a Fourier transform. The Fourier-transformed receiving signal is multiplied with a Fourier-transformed weighting function. The resultant product is subjected to an inverse Fourier transform to be used for calculating an antenna radiation pattern. A holographic multiple-beam antenna is also disclosed.

Multiple-beam antenna system

An auto-tuning controller includes a fuzzy resonator for the adjustment of control parameters used in the development of a control variable for controlling the operation of a system to be controlled. A characteristic variable extractor is provided which is responsive to an error signal representative of a difference between a reference value and a controlled variable value output by the system to produce a characteristic variable indicative of the operational state of the system. Based upon this characteristic variable, a fuzzy resonator adjusts the control parameters in accordance with predetermined reasoning rules stored in a reasoning rule memory.

Auto-tuning controller using fuzzy reasoning to obtain optimum control

A radar system for finding the location of a second flying object from a first flying object, comprises a nondirectional antenna for radiating a first radio wave from the first flying object, a second nondirectional antenna provided on the second flying object to receive the first radio wave and to radiate a second radio wave generated by modulating the received first radio wave and an array antenna provided on the first flying object to receive the second radio wave. The respective amplitudes of the signals given by the antenna elements of the array antenna are compared individually with a specified level and an operation for determining the direction of arrival of the second radio wave is executed using the signals given by all the antenna elements when either of the amplitudes of the signals given by the antenna elements is greater than the specified level.

A tracking radar system which includes a variable frequency oscillator for supplying to a vertical antenna array an oscillation frequency which is changed for each of a number of pulses transmitted from the antenna array. The antenna array transmits an electric wave toward a target at a low altitude and receives an echo from the target. An electronic computer estimates an elevation angle of the target from the echo received by the antenna array according to array aperture sampling technique for each pulse. An averaging circuit averages those estimated elevation angles of the target to provide its elevation angle. Alternatively, the oscillation frequency may change for each of finite time intervals.

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Kanagawa, Japan

Michimasa Kondo